☂️ C interoperability improvements

[kateinoigakukun]

This is an umbrella ticket

Motivation

It has been one of the major pain points of porting existing software using SwiftWasm as we use different libc implementation, wasi-libc, than other platforms, and wasi-libc uses some code patterns that are not friendly for Swift's existing C interoperability feature.

Detailed context

Improving the feature should reduce the cost of future porting works.

• stdio FILE not available in WASILibc? #2480
• Pointers needed on WASILibc #2313
• WASI/Wasm: withVaList(_:) produces a va_list with the wrong type swiftlang/swift#72398
• [SR-4096] Generated interface of #define XXX (<constant expression>) isn't created swiftlang/swift#46679
• [SR-2401] Macros with bitwise operations should be imported swiftlang/swift#45008
• [SR-485] C macros of the form ((long long)-1) should be imported swiftlang/swift#43102
• [SR-2402] Clang importer should import nullary function-like macros swiftlang/swift#45009